My Homebrew Copper Tube Dipole for 10 Meters

by Dean Moore, CD5846 and Ex-ZP6XD

I had constructed and used several more common wire dipoles, both in Paraguay and in Chile, using No. 14 or No. 12 insulated electrical cables and they worked ok with relatively low SWR. But since I live in Chile which is the world's largest exporter of copper, and since I had some copper tubes lying around that were left over from the construction of our new home in 2008, I decided to construct a new copper tube dipole especially cut for the lower part of the 10 meter band. My main goal was experimenting to see if a copper tube dipole would give better results than a copper wire dipole. To eliminate the suspense upfront, I can tell you the copper tube dipole performs much better than the wire to the point that even I am amazed! It works much better than the expectations of my wildest dreams! More on that later in the article. Now for some construction details.

The Beginning

I will admit that I'm not an expert antenna designer and don't fully understand all the theory and calculations of baluns, etc, so I must give credit where credit is due. I enjoy constructing and actually using antennas but I don't have a PhD in complex theoretical antenna design calculations through systematized incremental timephase projections, etc, etc! My good friend Manfred, XQ6FOD, one of the few "Superior" class operating hams in Chile helped me with the design of the balun for this antenna. He told me exactly how many turns to make, what the inside diameter of the coils should be, where to locate it, etc, for which I am very grateful!

Step One - The Center Feedpoint Connector

Center Feedpoint Connector

The main center TEE is a standard PVC part for 32mm tubes. Extending downward is a 32mm tube about 6" long which will become the area of the balun and the tube itself will go into a reducer from the 63mm main pipe antenna support pole. In both sides of the TEE is a PVC reducer from 32mm to 20mm. At this point I had to find some type of bushing or sleeve adaptor that would fit into the 20mm reducers and further reduce it to a good fit for the 3/8" diameter rigid hard copper thin wall pipes that will be the antenna. All I could find were the orange colored electrical bushings but they were just the right size! The hole in the top of the TEE is for a piece of 20mm PVC that would become the support structure to hold up the ends of the tube elements

and prevent them from drooping, as I feel that a perfectly horizontal dipole will be more effective than typical ones with the tips curved downward. I could be wrong but my logic tells me that a dipole antenna with ends that sag downward like most big HF yagi antennas will put out a somewhat distorted any case the best signal will result from a perfectly horizontal dipole from tip to tip. The hole in the side of the TEE is for the connecting wires from the elements to the coax balun.

Step Two - The Copper Tube Electrical Connections

The copper tubes were to be inserted until they contact the 20mm vertical PVC support, so the wires had to be soldered to the inside of the tubes so the tubes would pass through the PVC reducers, etc. So I oriented theshort connecting wires towards the side hole in the TEE as I inserted the tubes and then when the wires became visible I pulled them out with some needle-nose pliers. The following two images show the soldered connections and the basic center assembly:

Copper Tube Internally Soldered Wire Connectors

Dipole Basic Center Assembly

Step Three - The Balun

The balun is actually quite simple.....just seven full turns of the RG-58u Coax cable inserted through two drilled holes in the 110mm grey plastic tube which is about 5 inches long.

Balun for 10 meters

Step Four - The Finished Antenna

In these views you can see the finished installed antenna showing the 20mm center top support for the nylon strings that support the ends to keep them level. The supporting section of blue PVC pipe is 63mm and is about one meter long and fits over a 2" diameter thin wall steel tube that is 6 meters long. The installed actual height of the antenna is 21 feet above the ground at the copper tube level.

10m Dipole

10 Meter Copper Tube Dipole

Working Results

Now comes the fun part! Using this new dipole. Since it is mounted on a round steel tube, it is easy to manually rotate it. So I first turned it broadside to Europe and immediately worked some stations in PSK31 mode in France, Italy, Hungary, Argentina, Brazil, and the Czech Republic. Last evening it was raining here but I had the rig on anyway and anxious to make more QSO's with this new dipole! So I went out in the rain and turned it towards the USA. I made several QSO's and then it started pouring very hard here....a genuine downpour! Our home has a metal roof and I could barely talk to my wife it was raining so hard....and the roof is insulated! Just then I had another response to my CQ call from a station in New Jersey and he was using a vertical antenna. Our DirecTV was on and just lost the satellite signal which has only happened before during very strong storms. I was almost shocked to see 100% totally perfect copy on my screen when it was pouring rain like this, especially when he was using a vertical antenna. I had thought the heavy rain and dense clouds would have seriously attenuated my signals but we got through like we had clear skies! So thus far, I am extremely pleased and happy that I constructed this new dipole with copper tubes. I wonder now if even larger diameter copper tubes would be even better? However, for years in Paraguay I used a huge Sommer XP-807 Beam Yagi and honestly this simple copper tube dipole seems to perform as good or better! Comments appreciated. For my email, look up CD5846 on QRZ.COM.

An unrelated photo thrown in just for fun! I took this last year high in the Atacama Desert of Chile at an altitude of about 15,000 feet near the "Lago Chungara" (Lake Chungara) and near the border with Bolivia.

Atacama Desert at 15,000 feet near Lake Chungara

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